Switch discard investigation for early 2018
On February 1st, 2018, during a regular data quality review, we identified an increase in switch discards at sites with 10Gbps equipment connected to 1Gbps uplinks. We used our switch telemetry data to assess whether there were any negative consequences for tests contained in our SideStream or NDT data sets, and then we used the same data sets to determine whether our remediation strategy had any negative effects. In both cases, we found no observable effects, indicating that everything was below the noise floor for Internet performance data.
Our methods are open, and can be seen in the report, which is itself an iPython notebook to aid others in reviewing and reproducing our results.
The report:
- describes the cause of switch discards.
- describes the switch configuration changes made to prevent switch discards.
- describes the analysis used to conclude that the configuration change was positive.
- describes how to determine whether experiment data was affected by switch discards.